The use of membranes has already been proposed for the control of a distribution and apportionment valve of a fuel injection system, where small plates are soldered onto the membrane in the region of the valve seat for the purpose of reinforcement. However, in addition to the high supplemental cost required for the manufacture of such a membrane, there was the disadvantage that the small plates worked loose and led to valve failure and that the membrane exhibited internal stresses. The manufacture of a membrane having varying valve thicknesses by photochemical means (etching) has also already been proposed.
There was furthermore the problem of sealing the membrane from the valve housing, for which purpose sealing paste was used, but some of this paste frequently found its way into the working chamber of the valve and this resulted in fouling the valves.